Allied Machine 15YT-.421 Spade Drill Insert 27/64 in Cobalt

Product Description

The ALLIED MACHINE AND ENGINEERING 15YT-.421 is a cobalt spade drill insert designed for high-performance hole-making in demanding industrial applications. Part of the T-A series, this insert features a 132-degree point angle and a physical vapor deposition (PVD) TiN coating applied over a T15 cobalt substrate. The TiN coating reduces friction and extends tool life during interrupted cuts and high-feed drilling operations. With a seat size Y and a fractional inch measurement system, this insert mounts into compatible T-A series spade drill holders. Licensed machinists and tooling technicians working in production environments are the primary installers of this insert.

This insert is suited for drilling operations in steel, stainless steel, cast iron, superalloys, and titanium. The 27/64 inch diameter makes it appropriate for medium-bore applications in both job-shop and production-line settings. The T-A spade drill system is commonly used on CNC machining centers, lathes with live tooling, and dedicated drilling machines where replaceable-insert tooling reduces downtime compared to regrinding solid drills. The T15 cobalt grade provides heat resistance needed when cutting difficult materials such as stainless steel and titanium alloys.

Key Features

• 27/64 inch cutting diameter with seat size Y for T-A series holder compatibility
• T15 cobalt insert material for high heat and wear resistance
• TiN coating applied via PVD process to reduce friction and extend edge life
• 132-degree point angle suited for general-purpose and cross-hole drilling
• Rated for primary workpiece materials including steel, stainless steel, cast iron, superalloys, and titanium (ISO material codes P, M, K, S)
• Fractional inch measurement system; thickness 0.0938 inches

Compatibility

Designed for use with T-A series spade drill holders accepting seat size Y inserts at 27/64 inch diameter. Verify holder seat size and series before installation.

Installation Notes

This insert is installed and replaced by machinists or tooling technicians following standard spade drill system procedures. Ensure the machine spindle is fully stopped and locked out before removing or seating the insert. Use the correct seat wrench or torque key specified by the holder manufacturer to secure the insert without over-tightening the clamping screw. Inspect the holder seat for chips or damage before installing a new insert, as a contaminated seat will affect runout and tool life.